Electronic price labels provide numerous advantages in retailing and are growing in popularity. An electronic price label provides a superior substitute for a paper shelf label, and displays pricing and other information for a category of products, such as a size and brand of detergent or the like, suitably placed on a shelf in the vicinity of the label and available for purchase. In contrast to a paper label, which displays a fixed price and which must be individually changed whenever the price of a product is changed, an electronic price label can receive price information from a central database over a wire or through radio signals. An electronic price label is easy to update. Whenever a price change is desired, updated price information can be transmitted to every affected price label in a retail establishment. This is much faster and more convenient than changing paper labels, which must be changed or replaced individually, at considerable cost of time and labor.
While electronic labels are more versatile and more easily updated than are paper labels, they share a drawback common to many mechanical and electronic devices, in that they are subject to faults and breakdowns. An electronic price label which fails may provide incorrect price information, or no price information at all, and if the label fails without issuing an alert, it may continue in the failed condition for an indefinite length of time. If price labels are subject to failure without issuing an alert and it is desired to prevent labels from remaining in a failed condition, it is necessary to devote resources to performing periodic checks of each label. In establishments using a large number of labels, it will be necessary to perform relatively frequent checks, because the large number of labels in use will render it more probable that at least one label has failed. Because failures in electronic devices are difficult to predict, it would be advisable, in the absence of an automatic diagnostic or alert mechanism, to examine every label during every examination.
There exists, therefore, a need in the art for a self-diagnostic electronic price label adapted to automatically detect and report a fault.